Impact and reactant step-by-step rotary sprinkler head

ABSTRACT

A reversible part-circle step-by-step rotary sprinkler head having an impulse arm of the impact type in which the impulse arm has a first reactant portion disposed in a position thereon radially outwardly of the outlet and within the flow axis thereof when the impulse arm is disposed in the impacting position which has a first reactant surface shaped to deflect water issuing from the outlet in a direction opposite to that of the impact movement and establish a reactant force on the impulse arm acting to move the same in a direction toward the impacting position, the sprinkler body has a reactant element thereon disposed radially outwardly of the first reactant portion in a position spaced in the aforesaid opposite direction from the flow axis of the outlet so as to receive the water deflected by the first reactant surface when the impulse arm is disposed in the impacting position and to permit unobstructed flow of water issuing from the outlet when the impulse arm is spaced from the impacting position, the reactant element has a second reactant surface thereon shaped to deflect the water impinging thereon further in the aforesaid opposite direction and establish a reactant force on the sprinkler body acting in the impacting direction, the impulse arm has a second reactant surface portion disposed in a position to receive the water issuing from the second reactant surface which has a third reactant surface thereon shaped to deflect the water laterally in the impacting direction so that it issues therefrom in a direction generally parallel with the flow axis of the outlet and establishes a reactant force acting on the impulse arm to move the same in the aforesaid opposite direction.

United States Patent [191 Malcolm Nov. 11, 1975 IMPACT AND REACTANT STEP-BY-STEP ROTARY SPRINKLER HEAD [75] Inventor: William R. Malcolm, Sanger. Calif.

[73] Assignee: L. R. Nelson Corporation, Peoria.

[22 Filed: Nov. 1, 1974 21 App1.No.:520,206

Primur E.\'uminer-Robert S. Ward. Jr. Attorney, Agent, or Firm-Cushman, Darby & Cushman [5 7 ABSTRACT A reversible part-circle step-by-step rotary sprinkler head having an impulse arm of the impact type in which the impulse arm has a first reactant portion disposed in a position thereon radially outwardly of the outlet and within the flow axis thereof when the impulse arm is disposed in the impacting position which has a first reactant surface shaped to deflect water issuing from the outlet in a direction opposite to that of the impact movement and establish a reactant force on the impulse ann acting to move the same in a direction toward the impacting position, the sprinkler body has a reactant element thereon disposed radially outwardly of the first reactant portion in a position spaced in the aforesaid opposite direction from the flow axis of the outlet so as to receive the water deflected by the first reactant surface when the impulse arm is disposed in the impacting position and to permit unobstructed flow of water issuing from the outlet when the impulse arm is spaced from the impacting position. the reactant element has a second reactant surface thereon shaped to deflect the water impinging thereon further in the aforesaid opposite direction and establish a reactant force on the sprinkler body acting in the impacting direction, the impulse arm has a second reactant surface portion disposed in a position to receive the water issuing from the second reactant surface which has a third reactant surface thereon shaped to deflect the water laterally in the impacting direction so that it issues therefrom in a direction generally parallel with the flow axis of the outlet and establishes a reactant force acting on the impulse arm to move the same in the aforesaid opposite direction.

7 Claims, 4 Drawing Figures U.S. Patent Nov. 11, 1975 IMPACT AND REACTANT STEP-BY-STEP ROTARY SPRINKLER HEAD This invention relates to sprinkler heads and more particularly to step-by-step rotary sprinkler heads.

Step-by-step rotary sprinkler heads are well known in the art andconstitute probably the most widely used sprinkler head because of the very favorable water distribution pattern which can be achieved in the operation thereof.

This favorable distribution pattern can be achieved by virtue of the favorable radial reach ofthe water dur ing the periods of operation in which the water issuing from the outlet is unobstructed by the spoon of the impulse arm and the favorable radially inward distribution during the periods of operation in which the water issuing from the outlet is broken up and deflected laterally by engagement with the spoon of the impulse arm. The fact that during each impulse arm cycle the water distributed radially inwardly is displaced laterally or angularly with respect to the water distributed radially outwardly does not detrimentally effect the overall distribution pattern where full-circle operation is utilized since the lateral or angular displacement of two inner and outer full-circle distribution patterns has no effect. However, where part-circle operation is utilized, the

effect of the lateral or angular displacement is noticeable.

This detrimental effect has long been recognized in the art. For example, in Englehart US. Pat. No. 2,256,737, there is provided on the nozzle insert a fin or finger (7a of FIG. 6) which projects beyond the outer extremity of the outer reactant surface of the impulse arm spoon so as to be in the path of the water issuing laterally therefrom so as to deflect the flow back into a position of lateral or angular alignment with the unobstructed flow. With this arrangement, the fin becomes a reactant element on the sprinkler body and the surface thereof receiving the water a reactant surface.

Attempts to actually utilize the Englehart fin with the reactant surface disposed in a vertical radial plane, as shown in the patent, have not proven successful due to the excessive torque applied to the sprinkler body as a result of the reactant force applied to the reactant surface. Commercial sprinkler heads utilizing an Englehart-type reactant fin have usually provided a reactant surface which is angled downwardly to thereby reduce the horizontal component of the reactant force applied thereto by water impingement. This reduction in the reactant force is achieved with a corresponding reduction in the effectiveness of the fin to deflect the water back into alignment.

It is an object of the present invention to provide a sprinkler head having a reactant element on the sprinkler body which is operable to deflect the water laterally only when the water is being obstructed by the spoon of the impulse arm in which the torque applied to the sprinkler body by the reactant force applied to the reactant surface thereof is substantially reduced without a corresponding lessening of the effectiveness of maintaining the deflected water in angular alignment with the direction unobstructed flow. In accordance with the principles of the present invention, this objective is obtained by moving the reactant element radially inwardly into a radial position intermediate the inner and outer reactant surfaces of the impulse arm spoon. Torque reduction is achieved since the reactant force is applied to the reactant element through a much smaller lever arm. Moreover, the reactant surface need not be as large in area since it is contacted by the water much nearer the outlet at an earlier time before the flow has had an opportunity to break up. Thus, not only is the applied torque reduced by the reduction in surface area but the time of application is more nearly simultaneous with the application of theimpact force. Where the reactant element is disposed radially outwardly of outer reactant surface of the impulse arm spoon, much greater torque conditions exist due to the greater area needed to control the more dispersed flow, the greater lever arm through which the reactant force acts, and the later time of force application after impact. Moreover, this outermost positioning ofthe reactant element gives rise to size problems both in packaging and in operation. In terms of packaging, rather than to increase the package size, it is more usual to removably mount the fin to the sprinkler body so that it can be installed after opening the package. This gives rise to expense and possible misalignment problems. In terms of opera tion, a severe cost problem is presented where the sprinkler head is to be used in a pop-up system since it becomes necessary to substantially increase the diame ter of the pop-up housing just to accommodate the added radial extent of the fin.

Another object of the present invention is to provide a sprinkler head of the type described which is simple in construction, effective in operation, and economical to manufacture and maintain.

These and other objects of the present invention will become more apparent during the course ofthe following detailed description and appended claims.

The invention may best be understood with reference to the accompanying drawings wherein an illustrative embodiment is shown.

In the drawings:

FIG. 1 is a side elevational view of a sprinkler head embodying the principles of the present invention;

FIG. 2 is a front elevational view of the sprinkler head;

FIG. 3 is an enlarged fragmentary sectional view taken along the line 3-3 showing the reactant portions of the impulse arm in its limiting position; and

FIG. 4 is a view similar to FIG. 3 with the'reactant portions of the impulse arm disposed in spaced relation from its limiting position.

Referring now more particularly to the drawings, there is shown therein a step-by-step rotary sprinkler head, generally indicated at 10,. embodying the principles of the present invention. The sprinkler head 10 includes the usual sprinkler body I2, having a lower inlet portion 14 and an upper outlet portion 16 which communicates with the inlet portion. Formed in the outlet portion 16 is an outlet nozzle element 18 having an outlet 20 formed therein having a flow axis which, when the sprinkler head 10 is disposed in operative relation, extends generally upwardly and outwardly, as best shown in FIG. 1. Y

The sprinkler head 10 also includes the usual bearing assembly, generally indicated at 22. The bearing assembly 22 serves to mount the sprinkler head 10 in operative relation on a supply conduit (not shown) with the sprinkler body disposed in a vertically extending position for'rotational movement about a vertical axis coincident with the inlet 14. The bearing assembly 22 also serves to communicate the inlet 14 with a source of water under pressure within the supply conduit and to 3 provide a controlled resistance to the rotational movement of the sprinkler body I2 during operation.

The sprinkler head also includes an impulse arm. generally indicated at 24, which is mounted on the sprinkler body 12 for oscillatory pivotal movement about a vertical axis, which, as shown, is coincident with the axis of rotation of the sprinkler body 12. The impulse arm 24 is resiliently biased into a limiting position of abutment with the sprinkler body by any suitable biasing means as. for example. a coil spring 26 of conventional construction.

The preferred sprinkler head 10, as shown in the drawings, also includes a conventional reversing mechanism 28 operable to effect a reverse step-by-step movement of the sprinkler body 12, when the sprinkler head 10 is in a part-circle mode of operation, between two adjustable limiting positions determined by a pair of adjustable stops 30 and 32. Since the reversing mechanism 28 is of a conventional well-known nature (see the aforesaid U.S. Pat. No. 2,256,737) it is believed that no further detailed description thereof is needed.

The present invention is more particularly directed to the improved structure and mode of operation for effecting the oscillatory movement of the impulse arm 24 and the step-by-step rotary motion of the sprinkler body 12. Referring now more particularly to FIGS. 3

and 4, it will be noted that the impulse arm 24 includes a first reactant portion 34 disposed in a position thereon radially outwardly of the outlet and within the flow axis thereof when the impulse arm is disposed in its resiliently biased limiting position, as shown in FIG. 3. The reactant portion 34 includes a reactant surface 36 shaped to deflect the water issuing from the outlet 20 in a direction laterally away from the normal direction of step-by-step movement of the sprinkler body l2 as shown in phantom lines. The impingement of the water on the reactant surface 36 establishes a reaction force, indicated by the arrow 38, which acts on the impulse arm 24 in the aforesaid one direction tending to maintain the impulse arm in contact with the water flow.

As shown in FIGS. 3 and 4, the nozzle insert 18 is formed with an integral rigid arm 40 which extends outwardly therefrom spaced laterally from the flow axis of the outlet 20 in the aforesaid one direction. The rigid arm 40 includes an abutment surface 42 facing laterally in the opposite direction which is engageable by an opposed abutment surface 44 on the reactant portion 34 when the impulse arm 24 is moved into its limiting position. In the embodiment shown, the abutment surfaces 42 and 44 serve to impart an impact force to the sprinkler body 12 when interengaged which moves the latter an incremental step in the aforesaid one direction, the amount of such movement being resiliently controlled by the bearing assembly 22 in conventional fashion. It will be understood that other abutment surfaces may be provided, if desired.

The first reactant surface 36 deflects the water impinging thereon so that it issues therefrom laterally in a direction opposed to the direction of aforesaid incremental movement of the sprinkler body. In accordance with the principles of the present invention, the sprinkler body 12 has provided thereon a reactant element 46 disposed radially outwardly of the first reactant portion 34 in a position spaced laterally in the aforesaid opposite direction from the flow axis of the outlet 20 so as to receive the water issuing from the first reactant surface 36 when the impulse arm 24 is disposed in its limiting position. as shown in FIG. 3. and to permit unobstructed flow of water issuing from the outlet when the impulse arm is spaced from its limiting position as shown in FIG. 4. The reactant element 46 may be mounted in the aforesaid position by any suitable means and, as shown. the arm 40 is utilized to effect a rigid securement by means of a pair of spaced leg portions 48 formed integrally with the reactant element 46 and fixed to the outer end of the arm 40.

The reactant element 46 has a reactant surface 50 thereon which serves to deflect the water impinging thereon issuing from the first reactant surface 36 further in the same lateral direction as shown in phantom lines in FIG. 3. The impingement of the water on the reactant surface 46 establishes a reactant force, represented by the arrow indicated at 52 in FIG. 3, which acts on the sprinkler body in the same direction as the impulse force.

The impulse arm 24 also includes a second reactant portion 54 which is disposed in a position to receive the water issuing from the second reactant surface 50 when the impulse arm is disposed in its limiting position, as shown in FIG. 3. The second reactant portion includes a third reactant surface 56 shaped to deflect the water laterally back into the aforesaid one direction so that it issues therefrom in a direction generally parallel with the axis of the outlet as clearly shown in phantom lines in FIG. 3. The impingement of the water on the third reactant surface 56 establishes a reactant force acting on the impulse arm in the direction indicated by the arrow 58 in FIG. 3, so as to move the impulse arm in the aforesaid opposite direction.

If desired, a spray diffuser pin 60 may be utilized with the sprinkler head 10 to perform its usual function. While the pin 60 could be mounted in the outer end of the arm 40, as shown, the pin is threadedly mounted within a threaded opening in the upper leg portion 48. In accordance with usual practice the pin has a knurled head on one end thereof and a conical point on the other. A coil spring 62 is mounted in surrounding relation to the pin between the head and leg portion to resiliently retain the same in any desired position of adjustment.

OPERATION The sprinkler head 10 embodying the principles of the present invention is operable to perform an overall sprinkling cycle in which water is distributed within a part-circle pattern, the angular limits of which are determined by the setting of the adjustable stops 30 and 32. For purposes of illustration it is assumed that the stops 30 and 32 are set to provide a half-circle pattern. The cycle of operation will be described beginning with the sprinkler head disposed in a position intermediate the ends of the sprinkler pattern commencing with the communication of water under pressure therewith. It will be understood that prior to the communication of water under pressure with the sprinkler head 10, the impulse arm 24 will be disposed in its limiting position as illustrated in FIGS. 1-3 by virtue of the resilient bias provided by the coil spring 26. When the water is communicated with the sprinkler head, the water flows outwardly of the outlet 20 and impinges first upon the first reactant surface 36 which then directs the water onto the second reactant surface 50 which, in turn, directs the water onto the third reactant surface 56. As previously indicated, the impingement of the water on each of the reactant surfaces establishes a reactant force having a tangential component with respect to the vertical axis of rotation of the sprinkler body I2 and impulse arm 24, as indicated by the arrows designated 38,

52, and 58 respectively. It will be noted that the reac- I tant forces represented by the arrows 38 and 58 act upon the impulse arm whereas the reactant force represented by the arrow 52 acts upon the sprinkler body. With respect to the impulse arm, since the reactant force represented by the arrow 58 acts through a greater lever arm than the opposed reactant force represented by the arrow 38, the impulse arm 24 will be moved in a counter-clockwise direction as viewed in FIG. 3 or in a direction away from the flow axis and against the bias of the spring 26. When the torque acting on the impulse arm equals the increasing resistance of the coil spring 26, the movement of the impulse arm will be arrested and the spring 26 will commence the movement of the impulse arm in the opposite direction toward the limiting position shown in FIG. 3. As the impulse arm approaches the limiting position, as shown in FIG. 4, the first reactant surface 36 will be moved into the flow path of the water issuing from the outlet 20. This initial impingement of the water on the reactant surface 36 serves to insure that the impulse arm will be moved inwardly until the abutment surface 44 engages the abutment surface 42. The impact of these abutment surfaces serves to impart rotary motion to the sprinkler body 12 which rotary movement is controlled by the bearing assembly 22. As the impulse arm reaches the limiting position, the water impinging on the reactant surface 36 will be directed onto the reactant surface 50 which, as previously indicated, establishes a reactant force represented by the arrow 52, which applies additional torque to the sprinkler body tending to move the same in a clockwise direction as viewed in FIG. 3. The reactant surface 50 also serves to direct the water impinging thereon laterally onto the reactant surface 56. This establishes a reactant force on the impulse arm represented by the arrow 58 which, as aforesaid, will effect the outward movement of the impulse arm. It will be noted that the shape of the reactant surface 56 is such that the water impinging thereon issues therefrom in a direction which is generally parallel with the flow axis of the outlet 20. In this way, the water deflected by the impulse arm reactant surfaces is retained within the desired part-circle pattern. It will also be noted that when the impulse arm moves away from the limiting position to the position shown in FIG. 4 and beyond, the water issuing from the outlet will flow therefrom along the flow axis unobstructed by the reactant element 46.

It will be understood that the above cycle of the impulse arm is repeated moving the sprinkler body 12 in step-by-step fashion in a clockwise direction until the stop 30 is engaged by the reversing mechanism 28. At this point, the reversing mechanism is actuated to move an abutment into the position of movement of the impulse arm, so that as'it is moved away from the limiting position the abutment is engaged causing the sprinkler body 12 to move in a counter-clockwise direction. In

this way, the sprinkler body is moved in rapid step-bystep fashion through a return stroke until the opposite stop 32 is engaged and the reversing mechanism 28 is moved into its opposite position wherein the abutment is no longer disposed within the path of movement of the impulse arm and the operation in the first direction can take place.

It is important to note the effect of the reactant force represented by the arrow 52 in the cycle of operation;

First, it will be noted that the reactant surface 50 has a relatively small area. This is possible due to the fact that the reactant surface is disposed quite close to the outlet 20 so that the water issuing therefrom engages the same at a time before the stream has had an opportunity to significantly break up or disperse. Second, it will be noted that the lever arm through which the reactant force acts upon the sprinkler body 12 is relatively small, as compared for example with the lever arm through which the reactant force represented by the arrow 58 acts. Finally, it will be noted that the torque applied as a result of the impingement of the water on the reactant surface 50 is timed between the application of the torque as a result of the reactant forces represented by the arrows 38 and 58. In this way, the torque established as a result of the reactant force represented by the arrow 52 is minimized and operation throughout a full cycle with the sprinkler body 12 moving in step-by-step fashion in both directions is accomplished.

Of primary significance is the fact that during the cycle all of the water is substantially confined within the desired part-circle pattern. It will be understood that the present sprinkler head. while having particular advantages in part-circle operation, is useful in full circle operation as well. Likewise, it is not absolutely critical to the operation of the invention that the water issue from the reactant surface 56 be exactly parallel with the flow axis of the outlet 20 as some slight convergence or even divergence can be utilized. if desired.

It thus will be seen that'the objects of this invention have been fully and effectively accomplished. It will be realized, however, that the foregoing preferred specific embodiment has been shown and described for the purpose of illustrating the functional and structural principles of this invention and is subject to change without departure from such principles. Therefore. this invention includes all modifications encompassed within the spirit and scope of the following claims.

What is claimed is:

l. A step-by-step rotary sprinkler head comprising a sprinkler body having an inlet and an outlet having a flow axis, means for mounting said sprinkler body for rotation about a vertical axis with said inlet in communication with a source of water under pressure and with the flow axis of said outlet extending upwardly and outwardly, an impulse arm mounted on said sprinkler body for oscillatory movement about a vertical axis toward and away from a limiting position of abutment with said sprinkler body, means for biasing said impulse arm into said limiting position so as to impart an impact force to said sprinkler body in one direction, said impulse arm having a first reactant portion disposed in a position thereon radially outwardly of said outlet and within the flow axis thereof when said impulse arm is disposed in said limiting position, said first reactant portion having a first reactant surface shaped to deflect water issuing from said outlet in an opposite direction and establish a reactant force on the impulse arm acting to move the same in said one direction toward said limiting position,

unobstructed flow of water issuing from said outlet when said impulse arm is'spaced from said limiting position. said reactant element having a second reactant surface thereon shaped to deflect the water impinging thereon further in said opposite direction and establish a reactant force on said sprinkler body acting in said one direction, said impulse arm having a second reactant surface'portion disposed in a position to receive the water issuing from said second reactant surface, said second reactant portion having a third reactant surface thereon shaped to deflect the water laterally in said one direction so that it issues therefrom in a direction generally parallel with the flow axis of said outlet and establishes a reactant force acting on said impulse arm to move the same in said opposite direction.

2. A sprinkler head as defined in claim 1 including adjustable reversing means for effecting movement of said sprinkler body in the opposite direction between two adjustable limiting positions as a return stroke in a part-circle repetitive cycle the operative stroke of which includes movement of said sprinkler body between said two adjustable limiting positions in said one direction as aforesaid.

3. A sprinkler head as defined in claim 2 wherein said reversing means includes means for effecting said return stroke by rapid oscillatory movements of said impulse arm.

4. A sprinkler head as defined in claim 1 wherein said reactant element is fixed to said sprinkler body.

5. A sprinkler head as defined in claim 1 wherein said sprinkler body outlet is defined by a nozzle insert fixedly threadedly engaged with said sprinkler body, said nozzle insert having a rigid arm extending outwardly therefrom spaced laterally in said one direction from the flow axis of said outlet.

6. A sprinkler head as defined in claim 5 wherein said reactant element is rigidly secured to the outer end of said rigid arm by a pair of rigid webs spaced vertically on opposite sides of the flow axis of said outlet.

7. A sprinkler head as defined in claim 6 wherein said rigid arm includes an abutment surface facing in said opposite direction engageable by said first reactant portion of said impulse arm when the latter moves toward its limiting position to apply said impact force. l l 

1. A step-by-step rotary sprinkler head comprising a sprinkler body having an inlet and an outlet having a flow axis, means for mounting said sprinkler body for rotation about a vertical axis with said inlet in communication with a source of water under pressure and with the flow axis of said outlet extending upwardly and outwardly, an impulse arm mounted on said sprinkler body for oscillatory movement about a vertical axis toward and away from a limiting position of abutment with said sprinkler body, means for biasing said impulse arm into said limiting position so as to impart an impact force to said sprinkler body in one direction, said impulse arm having a first reactant portion disposed in a position thereon radially outwardly of said outlet and within the flow axis thereof when said impulse arm is disposed in said limiting position, said first reactant portion having a first reactant surface shaped to deflect water issuing from said outlet in an opposite direction and establish a reactant force on the impulse arm acting to move the same in said one direction toward said limiting position, said sprinkler body having a reactant element thereon disposed radially outwardly of said first reactant portion in a position spaced in said opposite direction from the flow axis of said outlet so as to receive the water deflected by said first reactant surface when said impulse arm is disposed in said limiting position and to permit unobstructed flow of water issuing from said outlet when said impulse arm is spaced from said limiting position, said reactant element having a second reactant surface thereon shaped to deflect the water impinging thereon further in said opposite direction and establish a reactant force on said sprinkler body acting in said one direction, said impulse arm having a second reactant surface portion disposed in a position to receive the water issuing from said second reactant surface, said second reacTant portion having a third reactant surface thereon shaped to deflect the water laterally in said one direction so that it issues therefrom in a direction generally parallel with the flow axis of said outlet and establishes a reactant force acting on said impulse arm to move the same in said opposite direction.
 2. A sprinkler head as defined in claim 1 including adjustable reversing means for effecting movement of said sprinkler body in the opposite direction between two adjustable limiting positions as a return stroke in a part-circle repetitive cycle the operative stroke of which includes movement of said sprinkler body between said two adjustable limiting positions in said one direction as aforesaid.
 3. A sprinkler head as defined in claim 2 wherein said reversing means includes means for effecting said return stroke by rapid oscillatory movements of said impulse arm.
 4. A sprinkler head as defined in claim 1 wherein said reactant element is fixed to said sprinkler body.
 5. A sprinkler head as defined in claim 1 wherein said sprinkler body outlet is defined by a nozzle insert fixedly threadedly engaged with said sprinkler body, said nozzle insert having a rigid arm extending outwardly therefrom spaced laterally in said one direction from the flow axis of said outlet.
 6. A sprinkler head as defined in claim 5 wherein said reactant element is rigidly secured to the outer end of said rigid arm by a pair of rigid webs spaced vertically on opposite sides of the flow axis of said outlet.
 7. A sprinkler head as defined in claim 6 wherein said rigid arm includes an abutment surface facing in said opposite direction engageable by said first reactant portion of said impulse arm when the latter moves toward its limiting position to apply said impact force. 